Solar & Photovoltaic Planning

Solar Calculators

Calculate solar panel tilt angles, model monthly solar production using PVWatts, estimate array sizing, and plan off-grid solar battery storage with transparent formulas.

Available solar calculators

Interactive Planning Journey

Recommended Solar PV Engineering Workflow

Follow our 4-step engineering sequence to plan a complete grid-tied or off-grid photovoltaic system from appliance energy demand to storage:

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Engineering Standards & Technical Methodology References

Calculations, electrical losses, and design safety margins adhere to recognized engineering guidelines:

NREL PVWatts V8PV Performance Model AlgorithmNational Renewable Energy Laboratory (NREL)

Standardized location-aware solar irradiance, temperature derate, and inverter AC output modeling.

NEC Article 690Solar Photovoltaic (PV) SystemsNational Electrical Code (NFPA 70)

Standards governing PV array circuit sizing, overcurrent protection, and rapid shutdown requirements.

IEC 61215 / 61730Terrestrial PV Module Reliability & SafetyInternational Electrotechnical Commission

Design qualification and type approval for crystalline silicon photovoltaic modules.

Which solar calculator should I use?

To find your optimal panel angle:

Use the Solar Panel Tilt Calculator to find seasonal and year-round tilt angles based on your latitude, and compare roof orientations.

Deterministic calculations & verified laboratory models

Our solar tools pair local geometry heuristics with NREL PVWatts V8 solar irradiance data. Every technical assumption (losses, inverter efficiency, DC-to-AC ratio) is visible and user-editable.

Read the solar methodology or review laboratory sources.